From owner-svn-src-head@FreeBSD.ORG Wed Dec 24 22:58:09 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8ABA092D; Wed, 24 Dec 2014 22:58:09 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 5DABD2D43; Wed, 24 Dec 2014 22:58:09 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id sBOMw9fV000517; Wed, 24 Dec 2014 22:58:09 GMT (envelope-from rmacklem@FreeBSD.org) Received: (from rmacklem@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id sBOMw9fX000516; Wed, 24 Dec 2014 22:58:09 GMT (envelope-from rmacklem@FreeBSD.org) Message-Id: <201412242258.sBOMw9fX000516@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: rmacklem set sender to rmacklem@FreeBSD.org using -f From: Rick Macklem Date: Wed, 24 Dec 2014 22:58:09 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r276192 - head/sys/kern X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Dec 2014 22:58:09 -0000 Author: rmacklem Date: Wed Dec 24 22:58:08 2014 New Revision: 276192 URL: https://svnweb.freebsd.org/changeset/base/276192 Log: Modify vop_stdadvlock{async}() so that it only locks/unlocks the vnode and does a VOP_GETATTR() for the SEEK_END case. This is safe to do, since lf_advlock{async}() only uses the size argument for the SEEK_END case. The NFSv4 server needs this when vfs.nfsd.enable_locallocks!=0 since locking the vnode results in a LOR that can cause a deadlock for the nfsd threads. Reviewed by: kib MFC after: 1 week Modified: head/sys/kern/vfs_default.c Modified: head/sys/kern/vfs_default.c ============================================================================== --- head/sys/kern/vfs_default.c Wed Dec 24 19:47:50 2014 (r276191) +++ head/sys/kern/vfs_default.c Wed Dec 24 22:58:08 2014 (r276192) @@ -401,17 +401,23 @@ int vop_stdadvlock(struct vop_advlock_args *ap) { struct vnode *vp; - struct ucred *cred; struct vattr vattr; int error; vp = ap->a_vp; - cred = curthread->td_ucred; - vn_lock(vp, LK_SHARED | LK_RETRY); - error = VOP_GETATTR(vp, &vattr, cred); - VOP_UNLOCK(vp, 0); - if (error) - return (error); + if (ap->a_fl->l_whence == SEEK_END) { + /* + * The NFSv4 server will LOR/deadlock if a vn_lock() call + * is done on vp. Fortunately, vattr.va_size is only + * needed for SEEK_END and the NFSv4 server only uses SEEK_SET. + */ + vn_lock(vp, LK_SHARED | LK_RETRY); + error = VOP_GETATTR(vp, &vattr, curthread->td_ucred); + VOP_UNLOCK(vp, 0); + if (error) + return (error); + } else + vattr.va_size = 0; return (lf_advlock(ap, &(vp->v_lockf), vattr.va_size)); } @@ -420,17 +426,19 @@ int vop_stdadvlockasync(struct vop_advlockasync_args *ap) { struct vnode *vp; - struct ucred *cred; struct vattr vattr; int error; vp = ap->a_vp; - cred = curthread->td_ucred; - vn_lock(vp, LK_SHARED | LK_RETRY); - error = VOP_GETATTR(vp, &vattr, cred); - VOP_UNLOCK(vp, 0); - if (error) - return (error); + if (ap->a_fl->l_whence == SEEK_END) { + /* The size argument is only needed for SEEK_END. */ + vn_lock(vp, LK_SHARED | LK_RETRY); + error = VOP_GETATTR(vp, &vattr, curthread->td_ucred); + VOP_UNLOCK(vp, 0); + if (error) + return (error); + } else + vattr.va_size = 0; return (lf_advlockasync(ap, &(vp->v_lockf), vattr.va_size)); }